A puffball is a fungus that belongs to the Basidiomycota phylum, which encompasses several different families and genera of fungi. It is called a "puffball" because when it matures, its fruiting body bursts open to release a puff of brown, dust-like spores. Puffballs are natural decomposers, and are most often found in meadows, grassy areas, and on heaths and lawns. They vary dramatically in size and appearance, from small species that grow together in clusters to larger species like the famous giant puffball, which can reach 12 inches (30 cm) or more in diameter.
A puffball is a Basidiomycete, which means its spores are produced on a small, club-shaped structure called a basidia. It is distinguished by its gasteroid basidiocarp, which is also known as its fruiting body. Spores are produced inside of this basidiocarp, which stays closed until the spores have been released from the basidia. That happens when the fruiting body ripens, and the rind tears open from some mild pressure — like the impact of a raindrop, the force of the wind, or someone other impetus. Spores then escape through the tear, creating a puff or cloud of dust.
A young puffball often looks like a white sphere, is fleshy in texture, and may or may not have a short stalk, depending upon the variety. The inside is made up of undifferentiated flesh, where the spores are produced in the interspaces of a compact rind. As the fungus matures, the flesh transforms into yellowish-brown or brown spore dust.
Many puffballs are edible before maturity, although once they begin to turn yellow inside and form powdery spores, they should not be consumed. They are easily distinguished from other mushrooms because of the fleshiness of their inner consistency. A puffball that is larger than a fist is unmistakable, but smaller puffball varieties should be checked carefully to avoid confusion with poisonous species. They can be differentiated from deadly varieties of the Amanitas — like the Death Cap mushroom — because they don't have stems or gills inside, and unlike stinkhorns, the interior will not have any slime.
Edible puffballs are known for having a rich, earthy flavor and can be found most frequently in the fall. They stand up well to all kinds of cooking and add a strong mushroom flavor that permeates throughout a dish. They usually cook in 7 - 15 minutes, and can be dehydrated or cooked and frozen for future use.